I solved it as I was writing this post! but anyway if you copied airplanes from this website to your aircraft folder and its in grey? that's because you're using direct x 10 preview wich won't work with these planes in this website. so just to let you know..I switched back to dx9 and its working!
this site is a wonder, just $5 a month
I am having the same problem onf the EC135 and EC145 helicopters. Both show up in the preview and simulation as grey or white with little or no texture colors. how do i switch Direct x to 9